Ultrafast Dynamics at Lipid-Water Interfaces.
Ultrafast Dynamics at Lipid-Water Interfaces.
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DOI：
10.1021/acs.accounts.0c00302
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发表时间：
2020-09-15
影响因子：
18.3
通讯作者：
Baiz CR
中科院分区：
文献类型：
--
作者：
Flanagan JC;Valentine ML;Baiz CR
脂质膜不仅仅是细胞区室之间的屏障;它们为分子环境提供了亲水和疏水相互作用之间的微调平衡，使蛋白质能够动态折叠和自组装以调节生物功能。描述脂-水界面的动力学对于理解从液-液相分离的热力学到界面氢键网络的皮秒级重组的分子复杂性是必不可少的。超快振动光谱，包括二维红外（2D IR）和振动和频（VSFG）光谱，是研究皮秒界面动力学的有力工具。二维红外光谱提供了一个键为中心的动态与亚皮秒的时间分辨率，振动频率是高度敏感的局部环境。最近，二维红外光谱已被应用于羰基和磷酸盐的振动本质上位于脂-水界面。界面特异性VSFG光谱直接探测水的振动模式，在脂质头基位置获得氢键强度和水组织。VSFG中的信号来自界面偶极贡献，直接探测头基排序和水取向，以提供界面的结构视图。在这个账户中，我们讨论了超快光谱在脂质膜上的新应用，这是一个在过去十年中经历了显着增长的领域。特别是，超快实验现在为日益复杂的膜提供了分子视角。超快、界面选择性光谱和模拟的强大组合为理解多组分膜及其功能开辟了新的途径。这个帐户突出了从最近的实验中出现的主要流行观点：（1）由于头部附近的氢键网络被破坏，与散装水相比，脂质-水界面处的水动力学较慢。(2)肽，离子，渗透剂，和共溶剂扰动界面动力学，表明在界面处的动力学受散装溶剂动力学，反之亦然。(3)界面环境通常由头基结构和取向决定，但酰基链内的疏水相互作用也调节界面动力学。超快光谱学对于表征脂-水界面的生物物理化学是必不可少的;然而，在解释拥挤的光谱以及设计适当的模型系统以捕获膜环境的复杂性方面仍然存在挑战。
Lipid membranes are more than just barriers between cell compartments; they provide molecular environments with a finely tuned balance between hydrophilic and hydrophobic interactions that enable proteins to dynamically fold and self-assemble to regulate biological function. Characterizing dynamics at the lipid–water interface is essential to understanding molecular complexities from the thermodynamics of liquid–liquid phase separation down to picosecond-scale reorganization of interfacial hydrogen-bond networks. Ultrafast vibrational spectroscopy, including two-dimensional infrared (2D IR) and vibrational sum-frequency generation (VSFG) spectroscopies, is a powerful tool to examine picosecond interfacial dynamics. Two-dimensional IR spectroscopy provides a bond-centered view of dynamics with subpicosecond time resolutions, as vibrational frequencies are highly sensitive to the local environment. Recently, 2D IR spectroscopy has been applied to carbonyl and phosphate vibrations intrinsically located at the lipid–water interface. Interface-specific VSFG spectroscopy probes the water vibrational modes directly, accessing H-bond strength and water organization at lipid headgroup positions. Signals in VSFG arise from the interfacial dipole contributions, directly probing headgroup ordering and water orientation to provide a structural view of the interface. In this Account we discuss novel applications of ultrafast spectroscopy to lipid membranes, a field that has experienced significant growth over the past decade. In particular, ultrafast experiments now offer a molecular perspective on increasingly complex membranes. The powerful combination of ultrafast, interface-selective spectroscopy and simulations opens up new routes to understanding multicomponent membranes and their function. This Account highlights key prevailing views that have emerged from recent experiments: (1) Water dynamics at the lipid–water interface are slow compared to those of bulk water as a result of disrupted H-bond networks near the headgroups. (2) Peptides, ions, osmolytes, and cosolvents perturb interfacial dynamics, indicating that dynamics at the interface are affected by bulk solvent dynamics and vice versa. (3) The interfacial environment is generally dictated by the headgroup structure and orientation, but hydrophobic interactions within the acyl chains also modulate interfacial dynamics. Ultrafast spectroscopy has been essential to characterizing the biophysical chemistry of the lipid–water interface; however, challenges remain in interpreting congested spectra as well as designing appropriate model systems to capture the complexity of a membrane environment.
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影响因子：
5.7
作者：
Costard, Rene;Greve, Christian;Elsaesser, Thomas
通讯作者：
Elsaesser, Thomas
影响因子：
5.7
作者：
Inoue, Ken-ichi;Singh, Prashant C.;Tahara, Tahei
通讯作者：
Tahara, Tahei
影响因子：
2.1
作者：
Bonn, Mischa;Bakker, Huib J.;Backus, Ellen H. G.
通讯作者：
Backus, Ellen H. G.
DOI：
10.1073/pnas.0908987106
发表时间：
2009-09-29
影响因子：
11.1
作者：
Kaiser, Hermann-Josef;Lingwood, Daniel;Simons, Kai
通讯作者：
Simons, Kai
影响因子：
15
作者：
Ingolfsson, Helgi I.;Melo, Manuel N.;Marrink, Siewert J.
通讯作者：
Marrink, Siewert J.